The invention relates to improvements in apparatus of the type disclosed in commonly owned U.S. Pat. No. 4,842,572 granted Jun. 27, 1989. The disclosure of this patent is incorporated herein by reference.
The patent discloses an apparatus which can be used to convert a continuous web, consisting of a series of panels which are integrally connected to each other along transversely extending fold lines, into a series of stacks each of which can contain a predetermined number of panels or sheets (e.g., 500 sheets per stack). The web is advanced lengthwise in such a way that its panels are in zig-zag formation and partially overlap each other (to form a so-called scalloped or imbricated stream) on their way into a substantially upright duct wherein they gather into a growing pile. The lower portion of the pile is separated from the panel immediately above it (along the fold line between such panel and the panel immediately below it) so that the separated lower portion of the pile constitutes a stack which is thereupon removed from the apparatus for storage or wrapping. Each panel can constitute a printed form and can bear printed information at one or both sides. The web is or can be weakened along the fold lines (e.g., by transversely extending rows of perforations) to facilitate separation of superimposed panels from each other. The severing of the web can be initiated by a counter which generates a signal when the pile in the duct contains a predetermined number of overlapping panels at the level beneath the plane of the severing tool.
A drawback of presently known apparatus of the above outlined character is that the severing tool is likely to damage or deface the panels which are immediately adjacent the path of movement of the severing tool toward severing or breaking engagement with the folded portion of the web at a predetermined level above the bottom wall of the duct. The danger of damaging and/or defacing the panels which are adjacent the path of movement of the severing tool is particularly pronounced if the panels of the web are relatively thin and readily deformable sheets of paper or the like, e.g., panels which can be used as second, third, fourth, etc. copies of printed forms. If the web offers a rather pronounced resistance to severing by the leader of the tool, the leader is likely to extract the neighboring panels from the duct and to thus cause damage to additional panels in the duct.